Non-volatile data storage devices, such as universal serial bus (USB) flash memory devices or removable storage cards, have allowed for increased portability of data and software applications. Flash memory devices can enhance data storage density by storing multiple bits in each flash memory cell. For example, Multi-Level Cell (MLC) flash memory devices provide increased storage density by storing 3 bits per cell, 4 bits per cell, or more. Although increasing the number of bits per cell and reducing device feature dimensions may increase a storage density of a memory device, a bit error rate of data stored at the memory device may also increase.
Error correction coding (ECC) is often used to correct errors that occur in data read from a memory device. Prior to storage, data may be encoded by an ECC encoder to generate redundant information (e.g., “parity bits”) that may be stored with the data as an ECC codeword. As more parity bits are used, an error correction capacity of the ECC increases and a number of bits required to store the encoded data also increases.
An occurrence of errors in data stored in a memory device may be influenced by the specific pattern of data programmed to the memory device. For example, cross-coupling effects between adjacent cells of a flash memory may be reduced when storing data patterns that cause adjacent cells to be programmed to have similar threshold voltages, while cross-coupling effects may be more pronounced for data patterns that cause adjacent cells to have widely differing threshold voltages. Other aspects of data storage, such as programming latency, power consumption during storage, and an amount of wear experienced by the memory device, may also be influenced by characteristics of data stored to the memory device.